The International Geophysical Year or IGY was an international scientific effort that lasted from July 1, 1957, to December 31, 1958.
The IGY encompassed eleven Earth sciences: aurora and airglow, cosmic rays, geomagnetism, glaciology, gravity, ionospheric physics, longitude and latitude determinations (precision mapping), meteorology, oceanography, seismology and solar activity.
Both the U.S. and the Soviet Union launched artificial satellites for this event; the Soviet Union's Sputnik 1 of October 1957 was the first successful artificial satellite. Other significant achievements of the IGY included the discovery of the Van Allen Belts and the discovery of mid-ocean submarine ridges, an important confirmation of plate tectonics.
There had been two preceding International Polar Years, from 1882 to 1883 and from 1932 to 1933. In the 1950s new instrumentation, including especially rocketry and seismography, inspired U.S. scientist Lloyd Berkner to propose a third polar year. The IGY was chosen to occur during a solar maximum, during which some unusual effects of the sun on the Earth might be observed.
For the history of the International Polar Years, see the article International Polar Year.
The International Council of Scientific Unions, a parent body, broadened the proposals from polar studies to geophysical research. More than 70 existing national scientific organizations then formed IGY committees, and participated in the cooperative effort.
IGY is featured in a song of the same name on Donald Fagen's solo album, The Nightfly:
- What a beautiful world this will be
- What a glorious time to be free